RU2460844C2 - Method for developing antifiltration coating - Google Patents

Abstract

FIELD: construction.

SUBSTANCE: method for developing an antifiltration coating includes preparation of an earth bed, installation of a watertight geomembrane in the form of cloths from polymer materials, installation of a protective liner from geotextile and arrangement of a protective layer. The protective geotextile liner is laid onto the antifiltration element from a geomembrane. A geogrid is fixed to the protective liner by spot welding with perforated walls of cells. Cells are filled with a filler and a gunning cement mix.

EFFECT: higher reliability and durability of a structure, watertightness of an antifiltration coating and hydraulic efficiency of a channel, provides for protection of an antifiltration element against mechanical damages in process of coating operation, eliminates water losses for filtration from canals and water reservoirs, prevention of waterlogging, salinisation and underflooding of valuable arable areas.

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Description

The invention relates to the field of hydraulic engineering and can be used to create impervious protection of reservoirs and canals.

A known method of creating an impervious lining of channels, (SU a.s. No. 1289952, E02B 5/02, E02B 3/16, BI No. 6 of 02.15.1987), including the creation of a protective coating from a shotcrete mixture deposited on a strip of fiberglass material, pre-laid on a film anti-filter screen located on the bottom and on the slopes of the channel.

The disadvantage of this method is the cracking of the coating during operation, followed by its destruction, due to a thin layer of shotcrete mixture and the absence of expansion joints.

A known method of strengthening road slopes and a device for its implementation (RU patent No. 2081234, E01C 5/00, E02B 3/12, E02D 17/20, BI No. 10 of 04/10/2006), including stretching the geogrids and fixing them on the lower layer and between themselves, as well as filling the geogrid cells with soil material, sowing grass seeds and compaction of the upper layer.

The disadvantage of this method is that this method provides only the function of strengthening the soil of the slopes from sliding and does not provide anti-filter protection of the slopes.

The closest technical solution is a method of creating an impervious screen with a geomembrane of polymer material (RU patent No. 2374386, E02B 3/16, BI No. 33 of 11/27/2009), including the preparation of a soil base, laying on it a waterproof geomembrane consisting of hermetically connected between a panel of polymer material, a device for compensating deformations of a geomembrane with a butt connection of panels in the places of the device of compensators and overlapping joints at the bottom and top with strips of material other than Methods and material geomembrane shield layer device from soil or other materials.

The disadvantage of this method is the low operational reliability due to erosion and sliding of the protective layer of the impervious screen from soil or other materials.

The essence of the invention lies in a method of creating an impervious coating with a geomembrane as an antifiltration element and a geogrid, which acts as a protective coating located on the slopes and edges of the channel, preventing water loss from filtering.

The technical result of the invention is the elimination of water losses through the antifiltration lining of the channel, increasing the operational reliability and durability of the antifiltration lining.

The technical result is achieved by using a geogrid with cells having perforated walls filled 2/3 with gravel or crushed stone, followed by filling them with a shotcrete mixture to the top. The geogrid is fixed by spot welding to a protective pad of geotextiles laid on an anti-filter element - a geomembrane, placed on a prepared base.

Antifiltration coating is arranged as follows. They prepare the bottom, edges and slopes of the channel, the base soil is cleaned of the roots of plants, boulders, and then compacted. On the edges of the canal, strokes are made, at a distance of 0.5 m from the edge of the canal, 0.3 m deep, in accordance with generally accepted recommendations (Instructions for the design and construction of anti-filtration devices from plastic film for artificial reservoirs. (SN 551-82). - M. : Stroyizdat, 1983. - 40 p. [Appendix 5]). On the prepared base of the channel, the antifiltration element, the geomembrane, is laid, and threaded into shrabs. The geomembrane should be used with a thickness of at least 1.0 mm, as material of smaller thickness is unstable to mechanical damage and will reduce the reliability of the structure. The geomembrane material must meet the requirements of GOST (Polyethylene film. Technical conditions. (GOST 10354-82) [Appendix 2]).

A protective gasket of non-woven geotextiles of medium or high density, necessary to prevent damage to the geomembrane, is laid on the geomembrane along the slopes and edges of the channel. In order to reduce the cost of the antifiltration coating on the bottom of the channel, a protective layer is not suitable, this is explained by the low probability of damage to the geomembrane, but when the channel passes in foothill areas or in places of water intake by mobile pumping stations, a protective coating is allowed along the channel bottom, which is similar to the protective coating of channel slopes .

A geogrid made of low-pressure polyethylene (GOST 16338-85) or high-pressure polyethylene (GOST 16337-77), with cells having perforated walls, is laid on a protective strip made of geotextile, along the sidelines and slopes of the channel. Then the geogrid is welded to the geotextile by spot welding (for example, with the PST-2 extruder), then the geogrid is laid in shtrabi. The height of the geogrid should be at least 100 mm, but it can vary (100 ÷ 200 mm) depending on the physicomechanical properties of the soil of the underlying base of the channel bed, climatic and other factors. Then make filling the stub with soil. Geogrid cells are filled at 2/3 of the height with aggregate - gravel or crushed stone, with a fraction of particles:

D _MIN > d,

where D _MAX , D _MIN - the maximum and minimum diameters of the particles of the filler;

h - cell height of the geogrid;

d is the diameter of the perforation holes.

On the filler of the geogrid along the slopes and edges of the channel, a shotcrete mixture is laid, with a layer thickness of 1/3 of the height of the geogrid, the grade of the sprayed cement mixture used must be at least M200. To improve the quality of the shotcrete mixture, namely to increase the ductility and crack resistance, complex additives are introduced into it, for example, liquid 136-41 (GOST 10834-76), sulphate-yeast mash (SDB), sodium nitrate NN (GOST 19906-74) and other

Component materials for the anti-filter coating device are delivered to the construction site by road, unloading and laying are done manually.

The use of such elements as a geomembrane and geogrid to create an antifiltration coating will increase the reliability and durability of the structure. The antifiltration element made of geomembrane will ensure the waterproofness of the antifiltration coating and increase the hydraulic efficiency of the channel. The device of the protective layer with the use of a geogrid will ensure the protection of the anti-filter element from mechanical damage during the operation of the coating.

A method of creating an impervious coating is illustrated in FIG. 1 and FIG. 2. Figure 1 - anti-filter coating of the channel (cross section). Figure 2 - diagram of the anti-filter coating (node A).

The method of creating an impervious coating includes the following elements: (1, 2) soil base of the slope 1; geomembrane 2; geotextile 3; geogrid 4; 5; fastening by 6 spot welding of geogrid to geotextile; placeholder 7 geogrid cells; shotcrete mixture 8.

The method of creating an antifiltration coating is performed as follows: (Fig. 1), a geomembrane 2 is laid on the prepared soil base of slope 1, a protective gasket of geotextile 3 is laid on top of it. Then, a protective coating of geogrid 4 is made along the slopes and edges of the channel and fastened 6 ( figure 2) by spot welding to geotextile 3. After backfilling the grooves 5, the cells of the geogrid are filled with aggregate 7 and shotcrete mixture 8.

The method of creating an antifiltration coating will provide high antifiltration efficiency, operational reliability, durability, as well as the stability of the coating on the slopes against the wave action of the flow.

Claims (1)

A method of creating an antifiltration coating, including preparing a soil base, laying a waterproof geomembrane in the form of panels of polymeric materials, laying a protective gasket from geotextiles and installing a protective layer, characterized in that a protective geotextile gasket is laid on the antifiltration element to which a spot welding is attached geogrid with perforated cell walls, which are filled with aggregate and shotcrete mixture.

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